1. Field of the Invention.
The invention relates to the field of air-conditioning apparatus, especially for motor vehicles.
2. Description of Related Art
The air-conditioning apparatus for vehicles generally includes an air-inlet duct fed selectively with outside air or with recycled air taken up from the passenger compartment, in which are mounted a blower and an evaporator, an air-conditioning casing receiving the cold air from the evaporator and including a cold-air transmission duct and a bypass duct in which is mounted a heat exchanger, these two ducts joining together in a mixing region intended to deliver air at the required temperature, and a distribution casing receiving the air from the mixing region and delivering it to various air-diffusion vents provided in the passenger compartment.
In the conditioning casing, a mixing flap is provided in order to share out the cold air delivered by the evaporator between a cold flow and an airflow passing through the heat exchanger. In an extreme position of this flap, all the air travels through the heat exchanger and, in another extreme position, no air travels through the exchanger.
The air-mixing region situated at the intersection of the cold-air duct and of the heating duct receives a cold-air flow and a hot-air flow at different speeds and in different directions. These two airflows would have to be mixed intimately, in order for the mixing region to deliver air at a uniform temperature.
However, it is observed that stratification of the air occurs. At the outlet from the mixing region, the air is colder on the cold-air-duct side and hotter on the bypass-duct-outlet side. In the distribution casing, the ducts for delivering air to the aeration vents are connected in such a way that the foot-aeration ducts, also called heating ducts, receive hotter air than that feeding the central or lateral aeration ducts of the passenger compartment. However, in general, the de-icing ducts receive colder air than that delivered by the aeration vents, which does not encourage demisting of the windscreen.
The mixing region is usually arranged in the upper part of the air-conditioning casing. The foot-aeration ducts, or more generally the ducts for aerating the lower regions of the passenger compartment and the rear region, therefore extend over the entire height of the said casing, and take up a not inconsiderable amount of space.
In certain air-conditioning apparatus, two mixing regions are provided, an upper mixing region intended to supply air to the de-icing vents and to the central and lateral aeration vents mounted on the dashboard, and a lower mixing region intended for supplying conditioned air into the lower part and the rear part of the passenger compartment. In other apparatus, the upper mixing region is intended for the front diffusion (de-icing, central and lateral aeration, front passengers"" feet), and the lower mixing region is intended for the diffusion to the rear of the passenger compartment. In this case, a supplementary duct is provided for transmitting cold air into the air-conditioning casing in order to feed this second mixing region. The heating duct is arranged between the two cold-air transmission ducts and supplies the two mixing regions with hot air. The additional duct also takes up a not inconsiderable amount of space, and it is necessary to provide a second mixing system in order to control the temperature of the air in the second mixing region, and a number of anti-return flaps.
The object of the invention is to propose an air-conditioning device for a motor vehicle which makes it possible to feed two mixing regions with a single mixing system, without requiring anti-return flaps and while ensuring homogenisation of the temperatures in each of the mixing regions.
The object of the invention is also to make the air circuit to the lower part of the apparatus more permeable and thus to benefit from a more substantial air throughput.
The object of the invention is also to propose a device for conditioning the air of the passenger compartment of a vehicle, which is compact, easy to produce and easy to assemble.
The invention therefore relates to a device for heating, ventilating and/or air-conditioning the passenger compartment of a motor vehicle, of the type including, in a casing, a first duct for transmitting a cold-air flow and a second duct, in which a heat exchanger is installed, for transmitting hot air, the said ducts being interposed between an air inlet and a mixing region delivering the mixed air.
According to the invention, this device is characterised in that it further includes an airflow-divider system which shares out the cold-air flow delivered by the first duct and the hot-air flow delivered by the second duct into a number of secondary flows, this divider system including, transversely and alternately, a number of cola-air passages having their inlets in the first duct and a number of hot-air passages having their inlets in the second duct, and in that the said passages feature a first series of outlets alternately delivering cold air and hot air into a first mixing region and a second series of outlets alternately delivering hot air and cold air into a second mixing region.
Advantageously, the airflow-divider system includes a number of parallel plates arranged transversely in the casing, at the junction of the first duct and of the second duct, these plates being linked in pairs in the first duct and the second duct by means of junction walls, so as to define the inlets of the cold-air passages in the first duct and the inlets of the hot-air passages in the second duct.
The following provisions are furthermore preferably adopted:
the plates, between the two series of outlets, includes edges attached to a transverse wall of the casing;
the said plates have an oblong shape and extend downstream of the heat exchanger in the second duct and across the outlets of the first duct and of the second duct;
the two mixing regions are arranged respectively at the extremities of the said plates.